Viewers saw Lucy Beale's little brother Bobby uncovered as her murderer, and Ian and Jane vow to keep his secret.
But how will they cope when an innocent person is arrested for killing Lucy?
Executive producer Dominic Treadwell-Collins said: "Viewers have seen Ian and Jane decide to keep it a secret, but this story will keep going on.
"What I can reveal is that someone else – an innocent person – will be arrested for this murder.
"Then carrying this guilty secret comes back to haunt Ian and Jane. How can you keep that a secret when someone else is facing jail for a murder they didn't commit?
"As a parent, what do you do? Do you go to the police and tell them that person is not the killer because your own son did it? How far will they go to protect their child?"
The drama for the Beales doesn't end there: Ian will soon get a huge shock when he finds out his mother Kathy isn't actually dead.
In 2006 he was told Kathy had died in a car crash in South Africa, but Gillian Taylforth made a surprise return during live week – 15 years after her last appearance.